Search for the standard model Higgs boson produced in association with top quarks and decaying into a b ¯ b pair in p p collisions at √ s = 13     TeV with the ATLAS detector

Research output: Contribution to journalArticle

  • Authors:
  • ATLAS Collaboration
  • Agni Bethani
  • Rafal Bielski
  • Ian Connelly
  • Brian Cox
  • Cinzia Da Via
  • Nicholas Dann
  • Giulio Forcolin
  • Alessandra Forti
  • James Howarth
  • David Lack
  • Frederick Loebinger
  • Stephen Marsden
  • Jiri Masik
  • Stephen Menary
  • Francisca Munoz Sanchez
  • Alexander Oh
  • Emily Orgill
  • Joleen Pater
  • Andrew Pilkington
  • Darren Price
  • John Raine
  • Jacob Rawling
  • Rhys Roberts
  • Savanna Shaw
  • Lee Tomlinson
  • Stephen Watts
  • Fabian Wilk
  • Terence Wyatt

Abstract

A search for the standard model Higgs boson produced in association with a top-quark pair, t ¯ t H , is presented. The analysis uses 36.1     fb − 1 of p p collision data at √ s = 13     TeV collected with the ATLAS detector at the Large Hadron Collider in 2015 and 2016. The search targets the H → b ¯ b decay mode. The selected events contain either one or two electrons or muons from the top-quark decays, and are then categorized according to the number of jets and how likely these are to contain b -hadrons. Multivariate techniques are used to discriminate between signal and background events, the latter being dominated by t ¯ t + jets production. For a Higgs boson mass of 125 GeV, the ratio of the measured t ¯ t H signal cross-section to the standard model expectation is found to be μ = 0.8 4 + 0.64 − 0.61 . A value of μ greater than 2.0 is excluded at 95% confidence level (C.L.) while the expected upper limit is μ < 1.2 in the absence of a t ¯ t H signal.

Bibliographical metadata

Original languageEnglish
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Volume97
Issue number7
DOIs
Publication statusPublished - 30 Apr 2018